Device for preparing a weft

ABSTRACT

THE DEVICE INCLUDES A THREAD GUIDE FOR CONDUCTING A WEFT THREAD, WHICH HAS A THREAD OUTLET THROUGH WHICH THE THREAD EMERGES FROM THE THREAD GUIDE, AND WHICH IS MOVABLE TO CARRY THE THREAD OUTLET THROUGH A SUBSTANTIALLY ELLIPTICAL PATH. TWO THREAD CLAMPS FOR INTERMITTENTLY CLAMPING THE THREAD ARE PROVIDED AT TWO POINTS WHICH ARE CENTRALLY LOCATED ON THE TWO LONG SIDES OF SUCH ELLIPTICAL PATH. A PAIR OF SHOULDER ARE LOCATED IMMEDIATELY INSIDE THE TWO SHORT SIDES OF THE ELLIPTICAL PATH, AROUND WHICH THE THREAD IS WOUND AS THE THREAD OUTLET MOVES THROUGH THE ELLIPTICAL PATH. TWO HOOK MEMBERS ARE CYLICALLY MOVABLE, SUBSTANTIALLY 180* OUT OF PHASE WITH ONE ANOTHER, IN TWO PARALLEL PATHS THAT INTERSECT THE ELLIPTICAL PATH ON OPPOSITE SIDES OF ONE OF THE THREAD CLAMPS. EACH HOOK   MEMBER ENGAGES THE THREAD SO AS TO DRAW A LOOP OF THE THREAD OUT OF THE ELLIPTICAL PATH. A CUTTER IS PROVIDED FOR SEVERING THE THREAD AT A POINT IN THE ELLIPTICAL PATH WHERE THE THREAD ENTERS THE OTHER THREAD CLAMP, AND A PAIR OF PUSHING NEEDLES ARE INTERMITTENTLY LONGITUDINALLY MOVABLE IN TWO PARALLEL PATHS THAT INTERSECT THE ELLIPTICAL PATH ON OPPOSITE SIDES OF THE OTHER THREAD CLAMP, FOR ENGAGING THE THREAD TO DELIVER IT TO A WEFT INSERTING DEVICE.

United States Patent [72] inventor Hubert Peter Van Mullekom Deurne, Netherlands [21] Appl. No. 828,290 [22] Filed May 27, 1969 [45] Patented June 28, 1971 [73] Assignee N. V. Machinetabrlek L. Te Strake Deurne, Netherlands [32] Priority May 28, 1968 [33] Netherlands [31 6807543 [54] DEVICE FOR PREPARING A WEI-T 1 Claim, 8 Drawing Figs.

[52] U.S.Cl 139/122, 139/127 [51] Int. Cl 003d 47/34 [50] Field ofSearch 139/116, 122-127, I 1; 66/125, 132

[56] References Cited UNITED STATES PATENTS 1,377,390 5/1925 Brooks 139/127 3,443,603 5/1969 Van Mullekom. 139/127 3,444,900 5/1969 Schaffer 139/125 r cowsrmvr SPEED DRIVE Primary Examiner-Henry S. Jaudon Attorney-Marshall & Yeasting ABSTRACT: The device includes a thread guide for conducting a weft thread, which has a thread outlet through which the thread emerges from the thread guide, and which is movable to carry the thread outlet through a substantially elliptical path. Two thread clamps for intermittently clamping the thread are provided at two points which are centrally located on the two long sides of such elliptical path. A pair of shoulders are located immediately inside the two short sides of the elliptical path, around which the thread is wound as the thread outlet moves through the elliptical path. Two hook members are cyclically movable, substantially 180 out of phase with one another, in two parallel paths that intersect the elliptical path on opposite sides of one of the thread clamps. Each hook member engages the thread so as to draw a loop of the thread out of the elliptical path. A cutter is provided for severing the thread at a point in the elliptical path where the thread enters the other thread clamp, and a pair of pushing needles are intermittently longitudinally movable in two parallel paths that intersect the elliptical path on opposite sides of the other thread clamp, for engaging the thread to deliver it to a weft inserting device.

CAM SHAFT PAIENTED JUN 2 8 9n SHEET 1 OF 2 CAM SHAFT DRIVE CONS TAN 7'' SPEED DRIVE DR/ VE DEVICE FOR PREPARING A WEFI' BACKGROUND OF THE INVENTION The invention relates to a device for preparing a weft to be used in weaving machines in which a thread is drawn from a thread package and which thread is to be inserted as a weft into the shed by weft inserting means. At this time the weaving machines having weft inserting means have such a high production speed that special measures are necessary to preparea weft which can be inserted into the shed by means of a weft inserting device such as a jet operated inserting device. In high speed looms drawing off a thread from a stationary thread package is very important and the drawing speed of the thread from the thread package should be uniform. In general rollers are applied for drawing the thread from the thread package which rollers have a constant speed of rotation such that the thread clamped between two adjacent rollers will .have an exact supplying speed. When now between the rollers and the weft inserting device a device for storing a measured length of a thread is provided, the length of thread can be immediately inserted into the weft without altering the constant drawing speed of the thread from the thread package. Particular measures are to be taken since the thread is drawn with a constant speed from the thread package, whereas the inserting of a measured length of a thread by means of the weft inserting device is intermittently performed.

SUMMARY OF THE INVENTION The object of the invention is to improve a device for temporarily storing a measured length of a thread in which use has been made of a hook member which runs around in a closed track for pulling a loop in the thread, which device according to the invention is characterized in that a thread guide cooperates with the hook member which thread guide is moved in a path which crosses the track of the hook member whereas in the path of movement of the thread guide a thread clamp and a guide shoulder have been arranged in such a manner that when the thread guide moves a loop is formed which runs from the thread clamp around the guide shoulder and back to the thread clamp from which loop a part is drawn by the hook member which runs in a closed track for forming a further loop of measured length in the thread. This has the advantage that during the period in which the hook member does not pull a loop in the thread the thread is presented in a closed path which facilitates the catching of the thread by the hook member whereas a period for taking up the thread is obtained during which period the thread still can be drawn from the thread package. Further the device according to the invention facilitates the arrangement of rollers for drawing a thread from the thread package. Further the device according to the invention is preferably adapted in such a manner that the hook member cooperates with a catching member for the thread, which catching member can be placed in two positions, whereas in one position the catching device holds a part of the loop of the thread and in another position releases this part of the loop in the thread.

By the provision of a movable thread guide it is possible to duplicate the device in such a manner that it is suitable to be used in weaving machines in which wefts in the shape of a hairpin are woven in the cloth, that is to say that the bight between the legs of the hairpin forms a selvage of the cloth. This manner of weaving need not be described as it is known per se and is performed in weaving machines in which the weft is inserted by jet operated weft inserting devices.

According to the invention such a particular application is possible when two endless chains or belts have been situated side by side whereas each endless chain or belt has been provided with a hook member for the thread which endless chains or belts are operated synchronously and the hook members for the thread have been situated 180 out of phase.

A practical embodiment of the device according to the invention is attained in that both chains or belts have been situated at such a distance, that a space for the formation of two loops of thread is present between the two chains or belts, whereas the hook member of each chain extends laterally over a part of the distance between the chains or belts. Each hook member of a chain cooperates with a separate catching member. In a practical embodiment of the device according to the invention the thread guide moves in a path which extends over the entire distance between chains whereas guide shoulder has been situated near each chain at both sides of a thread clamp around which shoulders the thread guide can move. Further a second thread clamp has been situated in the middle of the distance between both chains.

The continuous supply of the thread by means of the thread guide is possible because two thread clamps have been situated above each other and the thread guide runs along the closed path around the guide shoulders near the chains whereas during the movement of the thread guide from one shoulder to to the other a thread clamp will be passed whereas during the movement of the thread guide in the opposite direction the other thread clamp is passed, and both thread clamps are separately controllable for clamping the thread leaving the thread guide.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic perspective view of the main parts of the device according to the invention;

FIG. 2 is a cross section along the line lI-II in FIG. 1 and FIGS. 3-8 are diagrammatic plan views of the device shown in FIGS. 1 and 2 in which the successive steps of presenting the thread have been indicated.

Referring to the drawings, it is to be remarked that the device according to the invention for clearness sake has been reduced to its most elementary form and all parts which do not immediately relate to the invention such as driving and control mechanisms are omitted. In general it can be said that a device according to the invention is situated at each side of a weaving machine and the device according to the invention can be driven by a rotating shaft of the weaving machine. Further the controlling of different parts of the device according to the invention can be performed by means of for instance a cam shaft, as indicated in FIGS. 1 and 2, which is driven by a rotated shaft of the weaving machine.

In general the device according to the invention consists in a driving shaft I which for instance is connected by means of gear wheels 2 to a rotating shaft 3 of a weaving machine. The gear wheels 2 are adapted in such a manner that a correct speed of the rotatable shaft 1 in respect to the speed of operation of the weaving machine is obtained. To obtain a closed track two chain wheels 4a and 4b have been mountedon the shaft 1 around which chain wheels chains 5a and 5b respectively have been situated. Further the chains 5a and 5b run around chain wheels 6a and 6b respectively mounted on a shaft 7. A bracket 8a or 8b for a hook member has been mounted on each chain 5a or 5b. This bracket mounted on the chain 5a is visible in FIG. 1 and indicated by the reference number 8a. The bracket of the chain 5b is not visible as the brackets and 8 b are mounted out of phase on the chains 50 and 5b which run synchronously. The purpose of the bracket 8a is for carrying a rotatable shaft 9a provided with twin hooks 10a, which runs over a plate 11. The end of the shaft 9a remote from the hooks 10a is provided with a cam 12a and an eye-spring has been mounted between the bracket 8a and the cam 12a from which eye-spring one arm hooks behind the cam 12a owing to which the end l2a of the cam presses against a part of the bracket 8d, thereby holding the hooks 10a in an upright operative position. The cam 12a has been fastened to the shaft 9a in such a manner that when the cam 12a turns against the action of the spring the hooks 10a will turn also for a purpose which will be described. For clearness sake the hooks 10a with the shaft 9a on the chain 5a and the hooks 10b with the shaft 9b for the chain 5b have been indicated in the same cross section in FIG. 2. When desired the hooks can be provided with a roller for decreasing the friction with the thread.

There is so much space between the chains 50 and 5b above the plate 11 that a loop in the thread can be formed by means of the hooks a of the chain 5a and further a loop in the thread by means of the hooks 10b of the chain 5b. The spaces available for the loops have been separated by a partition wall 13. The wall 13 is a part of a cap 14 which in a lifted position has been shown in FIG. 1. The cap 14 in its mounted position has been shown in the cross section of FIG. 2. A part 15 of the partition 13 forms an anvil for two thread clamps situated above each other. This arrangement provides an upper thread clamp 16 above the anvil and a lower thread clamp 17 below the anvil. The anvil 15 can be also formed by means of a part of the cap 14. Grooves 18 have been provided in the cap 14, accommodate the hooks 10a and 10b. Further the cap 14 has been provided with guide shoulders 19a and 19b for purposes which will be described. For clearness sake, imaginary hooks 19d and 19'!) have been drawn in FIG. 1 to show the true location of the shoulders 19a and 19b because the cap 14 has been shown in lifted position in FIG. 1. Further the thread guide 20 has a thread outlet in its free end 21 which is bent towards the cap 14. The thread guide 20 has been adapted as a passage for the thread 22 which will be drawn from a stationary thread package 24 by means of rollers 23 which are driven at a constant speed as hereinbefore described and as indicated in FIG. 1. A sheaf of three thread guides, 20a and 20b have been shown in FIG. 1, and each of the thread guides 20a and 20b is situated in such a manner with respect to the thread guide 20 that the bent free end makes an angle of 120 with the bent free end of the thread guide 20. By turning the sheaf of thread guides another kind of thread can be presented to the thread clamps l6 and 17. Placing one of the thread guides 20, 200 or 20b in an operative position can be performed by a known selecting device for a thread as known per se in textile machinery. However, shifting from one thread supply to another forms no part of the present invention. Therefore, the use of a plurality of different threads will not be further described, and for simplicity the invention will be described as a device which usesonly one thread, drawn from a single thread package.

As rollers 23 for drawing a thread from a thread package are generally known these parts have been diagrammatically by a dotted line in FIG. 1.

The thread guide 20 is moved to carry its thread outlet under the thread clamp 16, over the thread clamp 17 and around the guide shoulders 19a and 19b in a substantially elliptical path which has been indicated by a dashdotted-line 25. Further two pushing needles 28a and 28b, which can be driven by a control mechanism for a purpose which will be described, have been situated on the cap 14. Catching members 26a and 26b have been situated in holes in the cap 14, which catching members cooperate with the hooks 10a and 10b. Cams 27a and 27b have been mounted on the cap 14 near the catching members 260 and 26b, which cams cooperate with cams 12a and 12b for a purpose which will be described. The catching members 26a and 26b and the cams 27a and 27b can be adjusted in a direction parallel to the partition 13 for adjusting the length of the loop in the thread.

The operation of the device and the functions of the parts of the device with respect to each other will now be described with reference to the FIGS. 3-8.

When forming the loops in the thread, it is assumed that the thread guide 20 with its end part 21 starts from a position which has been shown in FIG. 2. The thread guide with its end part 21 above the cap 14 moves in the direction of the arrow of the upper part of the path (FIG. 1) owing to which the thread 22 which has been drawn from the thread package by the rollers 23 and runs through the thread guide 20 comes under the thread clamp 16. As soon as the thread guide 20 passes the thread clamp 16, it will be closed and the thread 22 is clamped. The thread guide 20 moves further until it passes the shoulder 19a. This situation has been shown in FIG. 3. The thread guide moves from the position shown in FIG. 3 downwardly over a small distance and begins its reciprocal movement below the cap 14. The thread 22 comes now around the shoulder 19a. When the thread guide 20 moves the shaft 1 is also driven and the hooks 10a of the chain 50 come in front of the cap 14 as shown in FIG. 4. The thread guide 20 pauses in its movement just before the lower thread clamp 17 which has been diagrammatically shown by a square in the FIGS. 3-8 and for clearness sake somewhat displaced with respect to the thread clamp 16. This situation has been shown in FIG. 5. In the mean time the chain 511 moves the hooks below the cap 14 and the hooks catch a part of the thread which runs below the cap between shoulder 19a and the thread guide 20. A new loop in the thread will be formed by the hooks 10a which project in grooves 18 of the cap. During the formation of this new loop the thread is drawn through the thread guide 20 and slides around the hooks 10a.

The thread guide 20 remains in the position of FIG. 5 until the hooks 10a pass a catching member 26a. This situation has been shown in FIG. 5 in which the new loop in the thread 22 has been indicated by a dash line 22a.

When now the hooks 10a approach the catching member 26a the cam 12a which has been rigidly mounted on the shaft 9a will strike against a cam 27a. As a result the cam 12a will tilt against the action of a spring and the shaft 9a will rotate in such a manner that the hooks 10a bend backwards. At the same time the catching member 26a which is slidably mounted in the cap 14 will be depressed under control of the cam shaft drive which is indicated in FIG. 1. The catching member 260 has been provided with teeth at its lower side and the thread which will come free from the hooks 10a is caught by the teeth of the catching member 26a. The loop 22a will thus remain in a stretched position within the space above the plate 11 and below the cap 14. The hooks in their tilted position will pass the end of the loop 220 until the cam 12a releases from the cam 27a after which the hooks proceed in their operative position in the track of the chain and further in the reversal track for further operation later. In the mean time the thread guide 20 passes the thread clamp 17 and the part of the thread from the loop 22a to the thread guide 20 comes over the clamping surface of the thread clamp 17. When the thread guide has passes the thread clamp 17 the thread clamp will become operative and the thread will be clamped. The thread guide 20 moves further in direction of the shoulder 19b and then upwards until the thread comes above the cap 14. The step of operation in which the tread guide comes near the shoulder 19b in which step both thread clamps 16 and 17 are operative has been shown in FIG. 6. As soon as the thread clamp 17 becomes operative the length of the loop 22a has been fixed and the catching member 260 moves to its normal elevated position under control of the cam shaft drive so that thread can be inserted into the shed of the weaving machine e.g. by means of a jet nozzle 31 or by means of a gripper shuttle. A pushing needle 28a which can move in its length direction and has been mounted on the cap 14 has been adapted for presenting a thread to a weft inserting device e.g. a jet nozzle 31. The operation of such pushing needle is generally known and need not be described in detail. The needle 28a which is driven by a part of the weaving machine at the proper stage of the operation possesses a notch 29 at its point and the part of the thread which runs over the cap 14 between thread clamp 16 and the shoulder 19a comes into this notch and is pushed in the weft inserting device when the needle moves whereas at the same time the thread clamp 16 is released. After the loop 22a has been inserted into the shed as a weft the thread guide moves from the shoulder 19b over the cap 14 past the thread clamp 16. In the mean time the shaft 9b with the hooks 10b of the chain 5b is in front of the cap 14 (FIG. 7) and when moving further the hooks 10b will draw the thread which runs below the cap 14 between the thread clamp 17 and the shoulder 19b. During drawing of the new loop 22b, the thread will slide through the thread guide 20 and around the shoulder 19b and as a result the loop 22b will be formed. When now the cam 12b of the shaft 9b on the chain 5b strikes the cam 27b the hooks 10b will be tilted backwards and the catching member 26b will be depressed under the control of the cam shaft drive so that the end of the loop 22b will be caught in the teeth of the catching member 26b. At the same time the thread clamp 16 will become operative and the length of the loop 22b is fixed. This part of the thread which also runs between the shoulder 19b and the thread clamp 16 above the cap can 14 be presented to the weft inserting device by means of the presenting needle 28b. At the same time the thread will be cut by means of the knife 30, which is operated at this moment by the camshaft drive. Cooperation of a knife edge with a thread clamp is known per se and need not be described in detail. When the loop 22b is being inserted into the shed as a weft the clamping action of the thread clamp 17 will be released, the catching member 2612 also having moved to its upper, inactive position under the control of the camshaft drive so as to release the loop 22b, and the weft will come in a hairpin shaped manner in the cloth; that is to say the first leg of the hairpin is formed by the length of the loop 22a and the second leg is formed by the stretched length of the loop 22b. The bight between both legs of the thread forms the selvage of the cloth. When the loop 22b is being inserted as a weft the thread guide moves towards the shoulder 19a until the situation of FIG. 3 has been obtained again and the cycle of operation can be repeated.

It is evident that the controlling and driving of the various parts with respect to each other such as the movement of the thread guide 20, the operation of the thread clamps 16 and 17 and further the controlling of the catching members 26a and 26b and that of the needles 28a and 28b need not be described as such can be performed by means generally known in textile machinery e.g. by means of cam drums or cam dises.

I claim:

1. A device for use in conjunction with a loom to prepare a weft, comprising a thread guide for conducting a weft thread,

which has a thread outlet through which the thread emerges from the thread guide; and which is movable to carry the thread outlet through a substantially elliptical path, twothread clamps for intermittently clamping the thread at two points which are centrally located on the two long sides of such elliptical path, a pair of guide shoulders, located immediately inside the two short sides of such elliptical path, around which the thread is wound as the thread outlet moves through such elliptical path, two hook members which are cyclically movable, substantially l out of phase with one another, in two parallel paths that intersect such elliptical path on opposite sides of one of the thread clamps, and each of which engages the thread so as to draw a loop of the thread out of such elliptical path, a cutter for severing the thread at a point in such elliptical path where the thread enters the other thread clamp, and a pair of pushing needles which are intermittently longitudinally movable in two parallel paths that intersect such elliptical path on opposite sides of such other thread clamp, for engaging the thread to deliver it to a weft inserting device. 

